I'm sorry I'm not too familiar with 'Squills', but this is a very well done image and I really like it. It has that ruffled up and rough look. It's quite appealing and intriguing. The outlining has been well drawn out and it also looks distinct and artistic because it isn't so perfectly smooth.

i did however feel that the nib of the quill looked a bit too flimsy. And a bit more detail to the quill like showing the distinction between each node/hair/whatchamacallit would have looked nice. But that's just me being too picky. I do love the dark colouring and shading. Maybe a hue of red or blue could add aother dimension to the colour. Though even by itself, it's not hard to like. XD

This is a great drawing. And this just urges me even more to pick up a pencil and start drawing myself, even though I'm quite horrible at art. So keep the drawing quill flowing through the canvas. You're a great artist.

Honestly, when I first looked at this, I thought it was a snake. Be it the curves, the tongue-like ink point, or the details on the root of the quill that look like an eye and facial features, it just looks like a snake to me! But that's not a bad thing, mind you; it's just snake-like. Like Jafar..

My only advice for this quill is to watch your lines and shading a bit more carefully. Near the top of the inner quill, there's a mess of white littered in with the blue/gray/black, and on the head of the quill, there's an overlapping line. So just a tad bit more caution, and this'll be awesome!

Unlike Murtuza, I think it's alright without the definition of the nodes due to the unpredictable direction of the fray of the feather. If you were to define each line, it would be a ridiculous mess--or a ridiculous amount of work--so I'd just leave it how it is!

It's very blurry, which makes it feel very messy. The uniform thickness of the lines and how "lumpy" they look add to the messiness, as does the white border surrounding all the colors. It looks like you drew the lines with a dithered brush and then just filled them in with the paint bucket tool.

If you could tell me what program you used and how you drew the quill (with mouse, tablet, or touchpad), I could be more helpful.

As it stands, you might be interested in using Inkscape, which is a completely free vector program, to smooth out your lineart. This tutorial covers the basic process quite nicely.

You can also easily color in Inkscape, even with a touchpad, and the end results tend to be very clean and professional-looking. For instance, this image took me roughly three hours to draw by hand; I could have achieved a similar result in about half an hour using Inkscape (I just prefer drawing things by hand).

In addition, try varying the weights (widths) of your lines. It makes the image a bit more interesting and adds dimension to the object (like in this piece). Generally, the closer the object/part of, the heavier the lines; the more complex the details, the finer the lines; and the more shadowed the object/part is, the heavier the lines.

I'd also recommend studying pictures of tatter flight feathers. The flight feathers are the large hollow ones used for quills, and they're shaped differently than the quill as drawn. In addition, because of how a feather is structured, the tattering you've drawn doesn't make sense. It's almost as if the quill is made of tattered cloth rather than a plane of interconnected mini-feathers that have come unzipped near the ends. This picture shows things nicely.